Maybe I am missing something but by pressing the parking brake enough clicks, to disable the drl but not actuate brakes, do you not trigger the dash light that indicates your parking brake is on? If so and you have a brake pressure imbalance(like a broken line or something) how are you to know if the warning light is on all the time? I would rather a light tell me first about a leak when pressing the brake, like for say traffic slowing a tad, before pressing the brake pedal for heavy congestion ,if that situation occurs, to find out sooner and maybe allow me to use the transmission downshifting to help slow down and get off the road safely. I know it is a split system but at highway speed if that fault existed and you suddenly have to brake hard for traffic some may try pumping brakes not realizing what is happening perhaps making the situation worse or get distracted and may not be able to react quickly enough. With a warning you have time to manage the situtation get off the road and when slow enough that the tranny is pushing you instead of slowing you down use the brake for final stoppage before someone in front of you brakes to much from sudden heavy traffic congestion. That is if you get do a minor slow down when a leak has occured. It is a long shot but one some one might benifit from it especially if the run the master clyinder low on fluid and don't realize it. This of course applies only to people hear that disables the drl's with the parking brake.
The drl module has a connection from the module to (-)trigger the relay coil and illuminate dash indicator for drl's. If no trigger is present at the relay coil the it does not connect the lows directly to the power fuse on th i/p block to act as drl's. That would disable the drl's and dash light for same. Headlight switch should function normally.
If I am correct I would think it is a better idea then latch the parking brake a little.
Did that make any sense?